That looks like it's in series with the output. The 2540 delivers 200W RMS into 2 ohms, so that's 10A RMS. Your replacement would have to pass that current comfortably. You have to ask yourself why it's screwed as well - is one of the 2SK134 MOSFETs short-circuit?

Your best solution to replacing the inductor may be to rewind it yourself. It will have a rod down the middle (a ferrite bar core). You can cut off the orange heat-shrink sleeving and count the number of turns of wire on the core. Strip the burnt wire off and replace with some lacquered copper wire of the same gauge.

That looks like it's in series with the output. The 2540 delivers 200W RMS into 2 ohms, so that's 10A RMS. Your replacement would have to pass that JEFF comfortably. You have to ask yourself why it's screwed as well - is one of the 2SK134 MOSFETs short-circuit?

Your best solution to replacing the inductor may be to rewind it yourself. It will have a rod down the middle (a ferrite bar core). You can cut off the orange heat-shrink sleeving and count the number of turns of wire on the core. Strip the burnt wire off and replace with some lacquered copper wire of the same gauge.

Mezz is filtering the facts. That should read current. I relaxed. He got me.

Quote:

how can i test the mosfets incase they're dead too?

I could do with a better pic than this, cropped from an ad on the net.
Does any of the four big resistors look as thought it's had a hard life? That would be a clue if one MOSFET had gone short-circuit.
First cut; measure with a meter. You could really do with one that measures low resistances. Measure between the case of the 2SK134/2SJ49 and the end of the nearest big resistor to each transistor. You may be looking for the difference between a dead short and .66 ohms (+/- 10%)

If you know your way around electronics, circuit diagram is at Dr. Tube though this is slightly different to yours as they have two output inductors, CH1 and CH2, in parallel.

If the choke got that hot, you may also find that it's affected the solder joints to the board. Hopefully no tracks on the board are fried.

Actually, that isn't right. Though listed as 3540 and sharing some similarities, the diagram says it's for the 6010, 6020 & 6040. I'd be interested in better pics of both sides of the power module if you take it off.

OK, I have your higher quality pics.
What does the amp do at the moment, or have you been unwilling to switch it on??
Do you have a multimeter?
If you remove the nuts and bolts nearest the PCB on the output transistors, you should be able to measure resistance from the case to the other two pins on each transistor.
Would you feel confident to unsolder the A (+VE RD) and E (-VE BL) wires and tape them up so they're not touching anything?

Well, take the resistance measurements and give us a table of results - that might tell us whether you've got a short in a MOSFET

If you're happy to do it, you could unsolder and tape up those leads. If it still blows a fuse there's other damage, such as maybe the rectifier bridge gone short-circuit. If it powers up you can check the other channel's still good.

The diagram for the 3540 power amp (slave, I guess, as it has a little op-amp stage on the front and all the component numbers are different) shows separate transformer windings, rectifiers and smoothing for each channel, so if it still blows fuses the next step is probably to identify the power supply components for that channel and disconnect the bridge from the transformer.